A new Food and Drug Administration approved drug, Sucralfate, for the short-term treatment of upper gastrointestinal ulcers, has been proven to bind selectively to ulcerated areas in the upper G. I. tract. Several clinical trials have shown the safety and efficacy of Sucralfate in healing duodenal ulcers.
Radiologic studies are preferred by many as the first diagnostic procedure when intentinal disease is suspected. They are reasonably accurate in detecting ulcer disease in most instances. Radiologic studies are more widely available are are noninvasive, safer and less expensive then endoscopy, Applied Radiology, May/June 1982, pp. 20 and 120.
It is known that sucralfate binds to duodenal and gastric ulcers and to gastric erosions produced by ethanol and anti-inflammatory drugs. The affinity of sucralfate for defective mucosa is explained by the drug's viscous adhesivesness and the formation of polyvalent bridges between the negatively charged sucralfate polyanions and positively charged proteins present in high concentrations in mucosal lesions. Sucralfate also buffers acid, inhibits the action of pepsin, and adsorbs bile salts. These properties of sucralfate enable the drug to act as an effective barrier to the penetration of acid, pepsin, and bile salts. Sucralfate also binds to uninjured mucosa to a much lesser extent and is believed to exert a similar "barrier" effect on regenerated and normal mucosa. Other possible mechanisms for sucralfate's antiulcer effect include depletion of acid, pepsin, bile salts from the gastric secretion. Animal data show that the action of sucralfate is sustained because of its viscous adhesiveness, slow reaction with acid, and high affinity for areas with defectice mucosa, J. Clin. Gastroenterol 2 (supp 2):117-127, 1981.
Studies involving .sup.14 C-labeled sucralfate in rats using histoautoradiographic methods have also been reported, Duodenal Ulcer Gatric Ulcer, Sucralfate, a New Therapeutic Concept, edited by Wolfgang F. Caspary, Hanau, West Germany, published by Urban and Schwarzenberg, Munchen-Wien-Baltimore, 1981, pp 19-21. However, .sup.14 C-labeled sucralfate is unsuited for in vivo imaging in humans.
We have developed a simple method for labeling Sucralfate with Tc-99m and other radio labels. The resulting suspension is easily administered orally and imaging may be carried out with standard scintigraphic equipment. Preliminary animal and human studies show that the agent is stable in vivo and has clinical utility for the evaluation of gastrointestinal ulcer disease along with other diseases that are associated with loss of mucosal integrity.
The method is simple, should have ready patient acceptability and be associated with low radiation doses. It is believed that the present invention presents a significant advance in the art.